Methods permitting DNA sequence detection in real time and with high sensitivity are of great scientific and economic interest.1,2,3 Their applications include medical diagnostics, identification of genetic mutations, gene delivery monitoring and specific genomic techniques.4 Cationic organic dyes, such as ethidium bromide and thiazole orange, emit when intercalated into the grooves of double strand DNA (dsDNA), and serve as direct DNA hybridization probes, but lack sequence specificity.5,6 Energy/electron transfer chromophore pairs for strand specific assays exist, but require chemical labeling of two nucleic acids, or dual modification of the same altered strand (for example, molecular beacons).7,8 Difficulties in labeling two DNA sites result in low yields, high costs and singly labeled impurities, which lower detection sensitivity.9 
The recent introduction of peptide nucleic acids (PNAs) has provided an opportunity for new research and diagnostic applications.10,11 In PNAs, the negatively charged phosphate linkages in DNA are replaced with peptidomimetic neutral amide linkages. PNA/DNA complexes form more quickly, with higher binding energies, and are more specific than analogous DNA/DNA complexes.12 These enhanced properties result from the absence of Coulombic repulsion as occurs between negatively charged DNA strands. PNA complexes are thus more thermally stable and, by virtue of their backbone, less susceptible to biological degradation by nucleases, proteases and peptidases.13,14 Additionally, their general insensitivity to ionic strength and pH during hybridization provides a wider platform for DNA detection.18 
There is a need in the art for methods of detecting and analyzing particular polynucleotides in a sample, and for compositions and articles of manufacture useful in such methods.